KUBBE — owner’s manual

Digital Reverberation System · Model KB-79. Manual as PDF.

1. Introduction

Kubbe is an algorithmic reverb with three rooms instead of a list of algorithms: Hammam, Cistern and Valley. Each room is a fixed character — its own reflection timing, decay and colour. Nothing in it is recorded or measured from a real place; there are no impulse responses. You pick a room, not an algorithm.

It ships as VST3, AU and Standalone on macOS (Apple Silicon and Intel), and as VST3 on Windows (64-bit).

The three rooms

• Hammam — short and bright. Dense first reflections, a flutter between parallel walls, a ring in the low mids.
• Cistern — long and dark. Late, sparse early slaps and a long tail that moves slowly.
• Valley — open and rhythmic. Discrete echoes answer one by one, each answer darker and more blurred. With Echo Sync on, the echoes land on the beat grid.

2. Installation

Kubbe installs as an Audio Unit (AU) and a VST3 plug-in on macOS (Apple Silicon and Intel), and also runs there as a Standalone application. On Windows (64-bit) it installs as a VST3 plug-in.

macOS

1. Run the installer package (.pkg) you downloaded. It is signed with a Developer ID and notarised by Apple, so macOS opens it without any extra step.
2. Choose what to install: the VST3 plug-in and the Audio Unit and the Standalone application.
3. Restart your DAW, or make it rescan its plug-in list.

Windows

1. If Windows blocks the downloaded files: right-click the zip, choose Properties, tick Unblock, then extract.
2. Copy the .vst3 folder to C:\Program Files\Common Files\VST3\.
3. Rescan plug-ins in your DAW.

3. Panel tour

The panel reads left to right, the way it was laid out on the rack unit: name and model plate, then PLACE, then the display cluster, then the control groups, then the switches.

1. Name block — KUBBE, “Digital Reverberation System”, and the MODEL KB-79 plate.
2. PLACE — three lit selector keys for the rooms: Hammam, Cistern, Valley. Switching room lets the old tail ring out for 1.5 seconds instead of cutting it.
3. Decay display (scope) — the energy per 20 ms and the Schroeder decay curve, measured live on an impulse run through the engine, with the T60 it reads printed on screen.
4. VFD readout — shows the value of the control you last touched for two seconds, then falls back to the measured T60 of the current room.
5. DUCK meter — a VU-style needle showing how far the tail is ducked right now, in dB.
6. LEVEL group — Mix.
7. TIME group — Decay, Pre-delay, Pre-delay Sync.
8. SPACE group — Distance, Width.
9. TONE group — Low Cut, High Cut.
10. DYNAMICS group — Duck.
11. FREEZE and ECHO SYNC switches. Echo Sync is only enabled when Valley is selected.

4. Controls

Control	Range · default	What it does
Place	Hammam / Cistern / Valley · Hammam	Selects which of the three rooms the engine runs. Everything else shapes that room; it does not blend between rooms.
Mix	0–100 % · 30 %	Dry/wet balance, equal-power law.
Decay	×0.25–×3.00 · ×1.00	Multiplies the room’s own decay time (RT60). The scope always shows the measured result, not a nominal number.
Pre-delay	0–250 ms · 0 ms	Added on top of the room’s own pre-delay (Hammam 7 ms, Cistern 42 ms, Valley 0 ms). Disabled when Sync is on.
Pre-delay Sync	Off, 1/64–1/4 · off	Replaces the Pre-delay knob with a value synced to the host tempo.
Distance	0–100 % · 50 %	Near (0 %): early reflections up front. Far (100 %): more room, darker, less of the direct reflections. Also adds a low-pass on the wet signal: about 18 kHz at 0 %, 9 kHz at 50 %, 4.5 kHz at 100 %.
Width	0–150 % · 100 %	0 % collapses the wet signal to mono; 100 % is the room as built; up to 150 % widens it further.
Low Cut	20–1000 Hz · 20 Hz	High-pass on the wet signal only.
High Cut	1000–20000 Hz · 20000 Hz	Low-pass on the wet signal only. At 20000 Hz it is not fully open: each room has its own built-in cuts and Distance adds a low-pass.
Duck	0–100 % · 0 %	Follows the plugin’s own input — not an external sidechain. The tail steps back while that input plays, by up to 24 dB at full Duck, and the full 24 dB only for input at −12 dBFS or louder (about 6 dB at −30 dBFS). It ducks; it does not mute.
Freeze	On / off · off	Holds the tail indefinitely while input keeps playing, about 6 dB under the level it had while input was playing. New input is not added to the frozen tail; the dry signal still passes. Shown as “FREEZE HOLD” on the VFD.
Echo Sync	On / off · off, Valley only	Valley’s five slope echoes land on the beat grid — 3/4, 5/4, 7/4, 5/2, 7/2 beats — instead of fixed millisecond spacing.

5. Recipes

Vocal air (Hammam)

Place: Hammam · Mix: 15–20 % · Decay: ×0.8 · Distance: 30 % · High Cut: 8 kHz · Duck: 40 %

Keeps the dome’s bright, dense early reflections up front without smearing diction; Duck lets the tail breathe between phrases.

Dark sustain (Cistern)

Place: Cistern · Mix: 25 % · Decay: ×1.2 · Pre-delay: 60 ms · Low Cut: 120 Hz · Width: 120 %

Lets the late column slaps arrive on their own before the long, dark tail fills in — good for pads and slow synth lines.

Rhythmic slope echoes (Valley)

Place: Valley · Echo Sync: on · Mix: 30 % · Decay: ×1.0 · Distance: 60 %

The five slope answers land on 3/4, 5/4, 7/4, 5/2 and 7/2 beats against the host tempo — a rhythmic, self-darkening echo rather than a straight delay.

Freeze pad

Any room · Mix: 100 % · Freeze: on · Width: 130 %

Holds whatever is in the tail as a sustained drone while you play or automate over it; unfreeze to let it fall away.

6. Specifications

Item	Value
Formats	macOS (Apple Silicon and Intel): VST3, AU, Standalone · Windows (64-bit): VST3
Channel layouts	Mono → Stereo, Stereo → Stereo
Code signing	macOS installer signed with a Developer ID and notarised by Apple

The three rooms (nominal, Decay at ×1.00)

Room	Built-in pre-delay	Nominal RT60 (mid)	Low cut	High cut
Hammam	7 ms	≈ 3.0 s	170 Hz	11.5 kHz
Cistern	42 ms	≈ 6.8 s	85 Hz	6.2 kHz
Valley	0 ms	≈ 1.9 s	240 Hz	8.2 kHz

These are each room’s built-in numbers at Decay ×1.00. The Decay knob scales them directly; the scope always shows the T60 actually measured for the current settings, not this nominal table. Each room’s cuts are its own; Distance adds a further low-pass.

Measured behaviour (self-test)

• Decay: each room’s T60 lands within range of its nominal value; Decay ×0.5 gives a shorter tail; output is finite and silent 24 s after an impulse.
• Echo Sync: Valley’s first echo lands on the 3/4 beat at 90, 120 and 140 BPM, within 3 ms.
• Freeze: the tail holds flat for 4 s while input keeps playing, about 6 dB under the level before Freeze (5.8 dB measured).
• Duck: at 100 % the wet signal drops 12–26 dB; the full 24 dB needs input at −12 dBFS or louder. It ducks; it does not mute.
• Determinism: identical output, bit for bit, across runs and across block sizes 512 and 97.
• Level: the three rooms sit within 4 dB of each other at full wet.
• Room switch: no output step larger than the signal already has.

Not done yet

• Switching room again while the previous tail is still fading cuts that older tail.

7. Getting the plugin

Sign in on subverselab.com/launch and download. Install and open it in your DAW. Your licence key is on your Account page; the current versions do not ask for it.

Getting the plugin

1. Enter the Download Room with your account.
2. Download the macOS package or Windows zip.
3. Install the macOS package, or copy the Windows VST3 folder to C:\Program Files\Common Files\VST3\.
4. Open the plugin in your DAW.